The communications industry is rapidly changing to adjust to emerging technologies and ever increasing customer demand. This customer demand for new applications and increased performance of existing applications is driving communications network and system providers to employ networks and systems having greater speed and capacity (e.g., greater bandwidth). In trying to achieve these goals, a common approach taken by many communications providers is to use packet switching technology.
A common attack in the Internet is a coordinated distributed denial of service (DDoS) attack, in which many computers around the world simultaneously try to make apparently legitimate requests of a server, blocking access from regular clients. The computers mounting the attack are frequently members of botnets—that is regular computers that have unwittingly been compromised by malware. Since these are actual clients, from a broad array of networks, there is no simple way to sort the good requests from the bad. Frequently the only option is to manually block whole swaths of addresses, even though a lot of legitimate traffic is included in those swaths. An extreme example was the DDoS attack mounted against Estonia, in which the service providers ended up blocking all IP address not in Estonia—essentially they disconnected the Estonian Internet from the rest of the world.